A good ship for non-full elite ships (provided that they're able to kill it), but not as worth it for larger players.
Annihilator is a Reaper alien which had it's rewards changed. This alien hits much harder than most boss aliens you will find and can fire elite Hellstorms. Weaker ships don't stand a chance at killing these while stronger ships should take caution when taking these on. One simple advantage is that they offer 3 Xenomit and whilst this isn't much, it's still some, although for a Boss Kristallin with less health and damage, you can get 8. They're now worth your money when soloed but should still be done as part of quests only. Note these ships are not the mothership of the pirates, which is in fact the Battleray.